软土双线盾构施工地表变形实测分析与预测

依托杭州地铁2号线某盾构区间段工程，对软土区双线盾构施工引起的地表变形进行现场实测，分析地表变形的规律及双线Peck公式在软土地区的适用性，研究土体损失率的取值. 分析结果表明：软土地区双线盾构掘进引起的沉降绝对值较大且二次扰动效应明显强于其他土质；单环排土量与盾尾注浆压力的比值与地表最终沉降之间呈现较好的正相关性；土体损失率与单环排土量之间满足玻尔兹曼分布规律，即在盾构正常施工的情况下，土体损失率分布在一个有限区间内，随着单环排土量的增加而增大.

Prediction and analysis of surface deformation caused by twin shield construction in soft soil

A field test for twin shield construction in soft soil was conducted based on the project of Hangzhou Metro Line 2. The changing law of surface deformation and the applicability of twin peck formula in soft soil were analyzed based on the analysis of field measured data. The value of soil loss rate was analyzed. Results show that the sedimentation of the twin shield tunneling in the soft soil area is larger than the other soil. There is a positive correlation between the surface deformation and the ratio of the single ring excavated soil to the pressure of grouting. The loss rate of soil and the single ring excavated soil satisfies Boltzmann distribution. The loss rate is distributed in a limited interval, and increases with the increase of the amount of the single ring excavated soil.